Field of the Invention
The present disclosure relates to an electrophotographic photosensitive member, a process cartridge, and an electrophotographic apparatus.
Description of the Related Art
High-volume printing and high-speed printing are required of electrophotographic processes, and high response is required of electrophotographic photosensitive members, accordingly. Japanese Patent Laid-Open No. 2008-74714 discloses a technique using a charge transporting material having a high charge mobility in the charge transport layer for increasing the responsiveness of an electrophotographic photosensitive member.
If the charge transport layer acts as the surface layer or uppermost layer, it is further required to be resistant to externally applied electrical and mechanical forces. Accordingly, Japanese Patent No. 3492125 and Japanese Patent Laid-Open Nos. 2006-53549 and 2011-26574 disclose techniques using a photosensitive member including a surface layer made of a polyester or polycarbonate resin having a high mechanical strength. Japanese Patent 3492125 discloses an electrophotographic photosensitive member including a surface layer made of a polyester resin having a cyclohexylidene ring. Japanese Patent Laid-Open No. 2006-53549 discloses an electrophotographic photosensitive member including a surface layer made of a polyester resin containing a diphenyl ether dicarboxylic acid moiety. Japanese Patent Laid-Open No. 2011-26574 discloses an electrophotographic photosensitive member using a polycarbonate copolymer having a specific composition on a mole basis. Any of these disclosures describes that the durability of the electrophotographic photosensitive member is improved.